Anyway, I'm not an iPad lover (I still think that its an oversized iPod Touch), but as I have seen with other Apple hardware, the current iPad owners are most likely to change theirs to an iPad 2.
Will iPad1 hold back iPad2 ? i do not think so - i think you are putting your hopes a bit too high. normally the 2nd gen model fixes up all the problems/errors in the 1st generation, so adding things like a camera, bigger battery, better RAM optimisation (i.e. more RAM...